Method for sample identification in a mammal as well as a kit for performing this method

ABSTRACT

Method as well a kit for the performance of the method for the investigation of biological samples from a mammal for at least one component, wherein the method includes the following steps: (a) Administering at least one marker substance to a mammal; (b) Waiting for a length of time which is sufficient for the at least one marker substance to reach the location of sample removal; (c) Removing a biological sample from the mammal; (d) Investigating the biological sample for the presence and/or amount of at least one marker substance or a derivative thereof; and, if the at least one marker substance or the derivative thereof is detectable in the biological sample; (e) Investigating the biological sample for an analyte.

This application is for reissue of U.S. Pat. No. 7,820,444, issued Oct.26, 2010 from U.S. application Ser. No. 10/471,815, which is a nationalstage of international application PCT/EP02/02868, filed Mar. 14, 2002,which claims benefit of German application 10112470, filed Mar. 15,2001.

Notice: More than one reissue application has been filed for the reissueof U.S. Pat. No. 7,820,444. U.S. Ser. No. 14/033,118, filed Sep. 20,2013, is a divisional reissue of U.S. Pat. No. 7,820,444.

The present invention relates to a method by which a sample which wastaken from an excretion, a body fluid of a mammal or as a tissue sample,can be identified with relation to the origin of the sample and, in thisway, can be unequivocally assigned to the donor of the sample, wherebythe sample can be investigated for an analyte. Additionally, the objectof the invention is a kit for performing this method.

Diagnostic methods, methods for monitoring the course of a therapeuticmeasure, prophylactic routine investigations as well as forensic medicalinvestigations on man normally include the analytical investigation ofsamples in the laboratory, such as for example blood or serum sampleswhich were taken from the subject, as well as the investigation ofexcretions of the subject, such as for example urine. In view of themultitude of existing medical diagnosis and therapy methods for animals,a very wide variety of analytical methods with animal samples is todayevery bit as much common practice as well. Especially the problemshaving arisen in connection with intensive livestock farming, such asBSE sicknesses due to the feeding of animal meal or the admixing ofillegal food additives in the form of hormones and/or antibioticpreparations into the mast of livestock necessitate an extension ofregular control investigations in animal herds in agriculture.

In this context there is no question that any analytical investigationof a sample is only then meaningful if the results obtained in theinvestigation can also be unequivocally assigned to the respective donorof the sample in order to then initiate the correct response inevaluating the experimental results.

New analysis and test methods are continuously being developed as partof scientific-technical progress. Advances in molecular biology forexample allow the implementation of a series of detection methods basedon DNA analysis, by which certain sicknesses in man or in animals can bediagnosed.

Many newer analysis and detection methods also find application inforensic medicine or, due to constantly more challenging tasks of thelatter, owe their development to it, for example specific testingmethods for the detection of doping substances in athletes or for thedetection of drugs in vehicle drivers.

Due to the multitude of analysis methods implemented as well as theircomplexity, high standards are expected of the technical equipment aswell as of the personnel in the laboratories who perform theseinvestigations. Normally many samples have to be investigatedsimultaneously with modern analysis apparatus so that the problem of amix-up of samples unavoidably arises, thereby leading to an incorrectassignment of the investigation results with respect to the sampledonor. This problem is not new and is even exacerbated especially by therapid development of new analysis methods and the associated growingneed for their use.

Since the consequences of a mix-up or an exchange of the samples to beanalyzed are different but normally undesirable, there already exist awhole series of suggestions as to how to solve this problem.

These attempts at solutions relate mainly to an improved organization ofthe workflow in an investigative laboratory, where the following ofcertain rules of behavior is intended to minimize the danger of samplemix-up. However, since many protocol steps in these analysis methods arecarried out by laboratory personnel themselves, mix-ups attributable tohuman error cannot be completely ruled out.

Knowing this, computer-controlled monitoring of the respective protocolsteps to be performed with the sample is widely used, for example bylabeling the sample vessels with a computer-readable code so that therespective sample can be tracked during the entire investigationprocess, beginning with entry of the sample and including the processingand storage of the experimental results. This computer-monitored andcomputer-controlled sample analysis therefore allows a large number ofparallel determinations of different samples to without a significantdanger of mix-ups.

It is however clear to one of ordinary skill in the art that even thecleverest system of monitoring the samples to be investigated in alaboratory and of assigning the test results to these samples and, withthis assignment, to the sample donors, cannot completely exclude amix-up or an exchange of the samples, since only an inadequate markingof the samples or of the test results thereof can take place.

The described problem of a mix-up or an exchange of samples isespecially heightened in fields of application in which the test resultscan be used as incriminating evidence against the sample donor or, inthe case of a sample originating from a livestock animal, against theowner of the animal. In these cases there exists a special interest ofthe subject or of the owner to tamper with the test samples in order toavoid the generation of incriminating evidence.

However, it is especially in these cases that an unequivocal assignmentof the test results to the sample donor are especially important, sincecertain legal regulations can often only be enforced in this way.

The attempts at solutions which, in view of this problem, already existin the prior art for preventing tampering with the sample relateexclusively to the monitoring of sample removal. For example it iscommon practice that the submission of urine from subjects taking partin methadone therapy is supervised.

However, even the most clever monitoring and supervision of subjectsduring the submission of the urine sample will not completely prevent anexchange of the samples. In Germany 20,000 of the 120,000-140,000 drugaddicts are already treated with methadone. A major increase in thisnumber is to be expected in the future. Since methadone patients oftentake other narcotics as well as barbiturates and tranquilizers, acontrol of the substances taken by the patients is therapeuticallynecessary.

According to the guidelines for the implementation of methadone therapy,the urine must be checked at least once a week or, under certaincircumstances, even more frequently. Normally, submission of the urinesample under observation is not possible in normal doctors' officessince commonly only a small restroom is present and normally malemedical personnel are not at adequate disposal to accompany the malemethadone patients. The construction of restrooms suitable for samplesubmission under observation requires a high financial outlay. Just thecosts for such investment in the health office of Duesseldorf came to 50TDM.

Due to the commonly observed tampering of submitted urine samples, workis increasingly being done on analysis methods for detection of drugs insaliva discharge. Even if, in contrast to using blood, plasma or urineas test samples, a saliva sample can be obtained without a damagingintrusion or without intruding upon the subject's privacy, the danger ofa negligent mix-up of or an intentional tampering with the samples stillcannot be prevented.

The goal of the present invention is therefore to ensure an unequivocalassignment of the samples to the donor and, in this way, to overcome theproblems or disadvantages common to the prior art.

According to the invention this goal is met by providing a method forthe investigation of biological samples from a mammal for at least onecomponent, wherein the method includes the following steps:

-   -   (a) Administering at least one marker substance to a mammal;    -   (b) Waiting for a length of time which is sufficient for the at        least one marker substance to reach the location of sample        removal;    -   (c) Removing a biological sample from the mammal;    -   (d) Investigating the biological sample for the presence and/or        amount of at least one marker substance or a derivative thereof;        and, if the at least one marker substance or the derivative        thereof is detectable in the biological sample;    -   (e) Investigating the biological sample for an analyte.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the results of a chromatographic elution pattern of “MarkerA” (PEG 400) of a urine sample as described in Example 2. The resultsshow that Marker A can be used as a marker substance for identificationof a urine sample from a specified donor.

FIG. 2 shows the results of a chromatographic elution pattern of “MarkerB” (PEG 600) of a urine sample as described in Example 2. The resultsshow that Marker B can be used as a marker substance for identificationof a urine sample from a specified donor.

FIG. 3 shows the results of a chromatographic elution pattern of “MarkerC” (mixture of PEG 400 and PEG 600) of a urine sample as described inExample 2. The results show that PEG 400 and 600 can be used incombination as marker substances for identification of a urine samplefrom a specified donor.

The idea of the present invention was therefore to find a possibilitywith which the sample to be investigated can be marked while preventingthis marker from being removed from the sample by methods accessible toa layperson. The method is therefore suitable for example for monitoringmethadone therapy as well as for doping checks. Advantageous markingsubstances are in general characterized by a series of specificcharacteristics. These marker substances exert no pharmacological sideeffects on the organism of the mammal at the concentrations which arenecessary for detection of these marker substances in the blood, in theurine or other body fluids or in body excretions according to theinvention.

A derivative which is specifically formed from the at least one markersubstance can also just as well be used in place of the latter. By“derivatives” are to be understood all subsequent products which ariseas a result of a chemical transformation in the organism of the subjector in the removed sample, wherein however all subsequent products areexcluded which are not exclusively attributable to the transformation ofa specific marker in the subject organism or in the removed sample.

It is advantageous if the marker substances are soluble in a liquid,that the normal taste of the liquid such as for example juice is notchanged by the addition or that, following dissolving in water, nounpleasant taste of the resulting solution is caused by the markersubstances and, therefore, the subject can willingly drink the liquidcontaining the markers.

Advantageous marker substances are characterized in that they areabsorbed quickly through the intestinal mucous membranes and areexcreted from the subject in the urine. It is further advantageous ifthese marker substances in urine samples can be detected in as simple amanner as possible by detection methods already established in chemicalinvestigation laboratories such as for example common methods ofclinical analytical chemistry. According to the invention, it ispreferable to use marker substances which are not metabolized followinguptake by the subject.

Preferred marker substances are sugars or sugar derivatives such as forexample arabinose, erythrulose, myo-inositol, cis-inositol, mannitol,sorbose, rhamnose, sorbitol, xylose and xylulose, which are soluble inwater and which can be easily detected by enzymatic tests.

It is also advantageous to use isoprenoids, lipids, saccharides,polyols, polyethylene glycols, derivatives or mixtures of thesesubstances as the marker substance.

Especially preferred is the use of the method according to the inventionin the investigation of urine samples. For this, the marker substance ora combination of multiple marker substances is dissolved in a liquid,and the liquid is orally administered in that the subject drinks theliquid approximately 30 to 60 minutes before the urine submission.Polyethylene glycols or mixtures thereof are most preferably used asmarker substances for the investigation of urine samples.

It is especially preferable to administer multiple marker substancessimultaneously, wherein it is possible by the combination of markersubstances to develop a certain numerical code belonging to a respectivesample. In order to increase the safety against tampering, it ispreferred to administer a combination of at least 2, especiallypreferred of at least 3, very especially preferred of 5 markersubstances simultaneously.

Using a total of n marker substances, there exist 2^(n)−1 differentcombinations in a dual numeric system. Tampering with the samples by thesubject is therefore impossible since the subject would have to know thechemical nature of the marker substances, the numerical code for hisurine sample and the sequence of marker substances according to whichthe code is constructed.

The administration of the marker substance can be accomplished indifferent ways. By “administration” is to be understood the introductionof one or a multitude of marker substances into the organism of thesample donor. According to the invention, the marker substance or themultitude of marker substances can be administered to the sample donorpreferably parenterally or orally. It is especially preferred that themarker substance or the multitude of marker substances be taken up viathe digestive tract and that, during uptake, no metabolization of themarker substances takes places.

Depending on the type of the at least one marker substance administeredand the type of the sample to be removed, it is necessary prior to theremoval of the sample to be investigated to wait a certain “sufficientlength of time” before sample removal. This length of time representsthe time which the at least one marker substance requires to reach thelocation of sample removal. In the case of sample removal from acomponent existing separately from the sample donor, such as for examplesample removal from a body excretion, the time is to be understood asbeing that time which is required until the at least one markersubstance is present in the separable component and this component isseparated from the sample donor. The amount of time one must wait can beempirically determined, wherein however in most cases the correspondingvalues or methods for their determination are known in the prior art(van Rossum, J. M.: Kinetics of Drug Action. Handbuch derexperimentellen Pharmakologie, Vol. 47. Springer, Berlin 1977; Forth,W.: Allgemeine and spezielle Pharmakologie and Toxikologie.Bibliographisches Institut & F. A. Brockhaus, Mannheim 1988).

Sample removal occurs in different ways depending on the type of sampleto be investigated. In the case of the analysis of body excretions, partof the sample is taken up into a sample vessel and, after this time, isready for further investigation. In the investigation of human urine orstool samples, the samples can usually be furnished by the subjectsthemselves in that the subject is simply given a sample vessel. For theremoval of samples from body fluids or from tissue samples, a directoperation on the subject is normally necessary. Here, obtention of bloodfrom the subject can be accomplished using a suction pipette followingpricking or cutting of the skin with a disposable lancet or—in largerquantities—using an injection syringe or blood collection tube (German:Venule) after puncture of the vein. For the investigation of liquor, thelatter is obtained by lumbar, suboccipital or ventricle puncture.

By “biological sample” is meant the components of a mammal designatedfor the analytical investigation. Relevant here are body excretions,body fluids or tissue samples. The components making up the sample caninclude components of a mammalian organism which still exist in themammal at the time of sample removal as well as previous components ofthe mammal.

By “body excretions” or “excretion” are to be understood urine, stool,secretions from salivary, milk, tear and sweat glands.

By “body fluid” are to be understood extracellular liquids of amammalian organism like blood, serum and liquor.

By “mammal” are to be understood in addition to animals of this categoryman as well.

Preferably, the samples removed from or excreted by a mammal are bodyexcretions, body fluids or tissue samples.

By “tissue sample” is to be understood an organization of identicallydifferentiated cells obtained by a direct operation into the livingmammalian organism, as well as these cells' intercellular substance.Hair samples and samples of sloughed-off parts of skin are also to beunderstood as falling within the meaning of this term.

Depending on the type of the sample and the at least one markersubstance to be detected, the respective sample has to be prepared priorto the analysis method. The preparation steps can include centrifugationfor the separation of solid, non-solubilized materials in a liquidsample such as for example urine, solubilization or suspension of solidsamples such as for example stool, concentration by ion-exchangechromatography using Centricons, by precipitation with suitable reagentssuch as ammonium sulfate, adjustment of the pH value required for theanalysis method, homogenization of the sample such as by ultrasonicationor by using vibration cell mills in order to, for example, be able toinvestigate components from originally intact tissues, separation ofmaterials used in lysing the sample such as for example detergents andother preparation steps known to one of ordinary skill in the art.

A number of enzymatic, immunological, mass-spectroscopic andelectrophoretic detection methods as well as combinations of thesemethods are available for the determination of the presence or absenceof at least one marker substance in a sample. Preferably, detection isaccomplished by a coupled Gas Chromatography/Mass Spectrometry (GC/MS)or High Performance Liquid Chromatography/Mass Spectrometry (HPLC/MS)method or by High Performance Liquid Chromatography (HPLC) or GasChromatography (GC). These methods allow the very time-efficientinvestigation of, in particular, liquid samples or of samples which, dueto their preparation were transferred into a liquid. At the same time,these detection methods allow a high degree of automatization so that amultitude of samples can be analyzed in a short time and, in as far thechromatograms and, as the case may be, mass spectroscopic fractionationpatterns of reference substances already exist in the computerevaluation unit, the actual detection of the at least one markersubstance is also greatly simplified.

If it is determined as a result of the evaluation of the analysis methodapplied that the originally administered at least one marker substanceis present in the investigated sample, then this allows the unequivocalassignment of this sample to the subject. If this requirement isfulfilled, i.e. that the sample originates from the subject beinginvestigated, the actual investigation of this sample or, alternatively,of a second sample for an analyte takes place.

By “analyte” is to be understood at least one chemical substance,wherein the knowledge as to the presence or, as the case may be, also ofits concentration in the sample, allows a conclusion as to a past,expected or present condition of the sample donor. As an example, aconclusion as to an incorrectly functioning—becauseincomplete—resorption of glucose from the urine by the kidney tubules(glucosuria) in a subject is made possible on the basis of knowledge ofthe concentration of an analyte such as for example the glucoseconcentration in the urine of a urine sample, which was normallyenzymatically determined by means of glucose oxidase (GOD) orhexokinase. Analytes can further be intoxicants, medicines, metabolitesof the previously named substances, the detection of which in the sampleyields information as to the behavior or a treatment of the subject.

In addition to the use of the method according to the invention in humanmedicine, there also exist a multitude of further applications in theveterinary medical field and in agriculture. The method canadvantageously be used in the monitoring of adherence to regulations forthe use of feed additives in agricultural livestock mast farming.

If for example samples obtained from mast pigs are to be investigatedfor the presence of growth hormones or antibiotics or their metabolites,the use of the method according to the invention can avoid the problemof a tampering with the samples to be investigated by the owner of theherd of mast pigs.

Here, especially those marker substances are advantageous which remainin the animal over a long length of time—in the ideal case over theentire duration of masting—yet which are still continuously present in adetectable amount, for example in a body excretion. For this reason,those marker substances are advantageous which can be administered tothe animal as a time-release agent, by virtue of which for example atime-delayed yet continuous resorption through the intestinal mucousmembranes takes place and therefore the at least one marker substance isdetectable over a longer length of time, for example in a body excretionlike animal feces. Especially suitable samples are samples with whichboth the investigation for the at least one marker substance as well asthe detection or the concentration determination of at least one analytetakes place.

Another object of the present invention is a kit for performing thedescribed method for sample identification in a mammal, wherein the kitaccording to the invention includes a marker substance in a containersuch as a tablet vessel as well as, as the case may be, means foradministering the at least one marker substance to the mammal.

It is especially advantageous if this kit also contains at least onereference substance for the detection of the marker substance or themultitude of marker substances.

A kit according to the invention preferably contains, for the oraladministration of the marker substances, these marker substances in theform of individual water-soluble effervescent tablets. Alternatively,these effervescent tablets can also already contain the markersubstances as mixtures of multiple marker substances. The respectivesubstance code can then be taken from the label of the tablet vessel.

The kit can comprise effervescent tablets with varying concentrations ofmarker substances corresponding to the circle of people to whom themarker is to be administered, so that these marker substances can beapplied for example to children as well as adults without reaching aconcentration of marker substances in the subject at whichpharmacological side effects can arise.

It is especially advantageous if the tablet vessels contained in the kitare provided with a computer-readable code. Kits intended for themarking of urine samples of methadone patients preferably containtablets, capsules, or similar application forms in which both the amountof methadone to be administered as well as the mixture of markersubstances are available together.

Further advantageous embodiments of the kit according to the inventioninclude multiple reference substances by means of which the markersubstances can be easily identified in the chromatographic analysis ofthe sample, such as for example in the investigation of the urinesample.

In, for example, the investigation of the urine sample of a patienttreated with methadone, an ampoule tube can also be present in the kitaccording to the invention, which ampoule tube contains a mixture ofmarker substances solubilized in a suitable carrier means according tothe chosen chromatographic method, wherein this mixture correspondsexactly to the mixture present in the corresponding methadone tablets.

By a subsequent run on the same GC column, it can be determined veryquickly and with certainty due to the chromatography peaks of the markersubstances in a GC analysis whether the investigated urine sampleoriginates from the patient being treated with methadone.

EXAMPLE 1

For the further exemplary explanation of the method according to theinvention, an embodiment for performing the marking of a sample to beinvestigated is provided below.

The embodiment relates to the marking of a urine sample to beinvestigated and its subsequent investigation. The subject receives100-300 ml of liquid to drink, in which 1 g polyethylene glycol 600 issolubilized as a marker substance. Fruit juices, water, and otherliquids palatable to humans can be used as liquids to drink.

In place of polyethylene glycol 600, monodisperse fractions or mixturesof monodisperse fractions can also be used. Here, the laboratoryestablishes a substance code. Such a code is given in the following asfive monodisperse polyethylene glycol fractions. Here, “0” stands fornot present and “1” stands for present.

Substances Substances Code A B C D E 1 0 0 0 1 1 2 0 0 1 0 1 3 0 0 1 1 04 0 0 1 1 1 5 0 1 0 0 1 6 0 1 0 1 0 7 0 1 0 1 1 8 0 1 1 0 0 9 0 1 1 0 110 0 1 1 1 0 11 1 0 0 0 1 12 1 0 0 1 0 13 1 0 0 1 1 14 1 0 1 0 0 15 1 01 0 1 16 1 0 1 1 0 17 1 1 0 0 0 18 1 1 0 0 1 19 1 1 0 1 0 20 1 1 1 0 0

The substances A, B, C, D and E correspond to polyethylene glycolfractions with molecular weights:

A 530 B 574 C 618 D 662 E 706

After ingestion the subject was requested to wait at least 30 minutesand at the most 4 hours before urinating. The subject was allowed toconsume further liquids or solid food during this waiting phase. Thesubject did not have to be supervised during the waiting time. Thesubmission of urine by the subject took place without supervision.

The sample vessel was identified with a barcode label coding a jobnumber also contained on the computer-readable accompanying tag. On theaccompanying tag were noted the name of the subject, the desiredinvestigation as well as the combination of marker substances or thesubstance code. The sender is saved by the job number in the master dataof the lab computer. The samples were transported to the laboratory withthe accompanying tag. The accompanying tag was entered into the computerwith a card reader. The job was recorded in this way. Here, thesubstance combination or the substance code was also entered into thecomputer.

For the analysis for polyethylene glycol, the urine was centrifuged, 100μl of the supernatant was given on Nucleosil C 100-(C18), 3 μm (4.6×125mm) at a flow rate of 0.5 ml/min (methanol/water 5/95) and wasinvestigated for polyethylene glycol by detection with an RefractiveIndex (RI) detector. The chromatography peaks were identified aspolyethylene glycols by the retention times based on the referencechromatographies.

In this way, each investigated urine sample could be unequivocallyassigned to the respective subject via the substance code of thedifferent polyethylene glycol fractions used. The subject wassubsequently investigated for the analyte, i.e. an intoxicant to bedetected like heroin or its derivatives.

Sugars for marking body fluids can be used in the same manner asdescribed for polyethylene glycol fractions. These are determined fromurine or other body fluids via enzymatic detection reactions. Theanalytical detection methods required for this are known in the priorart (Methods of Enzymic Analysis, ed. Bergmeyer, H. U. VCHVerlagsgesellschaft mbH, Weinheim 1986).

EXAMPLE 2

For pre-analytical patient preparation, patients of drug ambulances weregiven 1 ml of polyethylene glycol 400 (“Marker A”), 600 (“Marker B”) ora mixture of 400 and 600 (“Marker C”) in 100 ml fruit juice. Patientswere supervised while drinking and asked to wait for at least 30 minprior to urine delivery. After that time patients were allowed tourinate without supervision. The urine tube was then labeled anddirectly transported to the site of analysis.

Before analysis, the sample were prepared as follows: 10 ml urine wascentrifuged at 10500×g for 10 min.

For polyethylene glycol analysis, the chromatograph was operatedisocratically at ambient temperatures in the column-switching mode.Because RI detection limits to isocratic mobile phases, eluent ofcleanup and analytical pump were identical, consisting of 44% methanoland 56% water. 100 μl supernatant of the centrifuged urine were injectedautomatically onto a (60×4.6 mm) precolumn filled with Nucleosil 100C18, 5 μm. With the eluent delivered by the clean-up pump at a flow of0.4 ml/min and a pressure of 36 bar, matrix impurities were dischargedto the waste, while the polyethylene glycol (PEG) fractions wereretarded on the stationary phase. After 120 sec the precolumn wasswitched by the six-port valve to the eluent stream of the analyticalpump, and the analytes were backflushed for separation with a flow rateof 0.5 ml/min and a pressure of 96 bar onto the analytical column,Nucleosil 100 C8 5 μm. Analysis time took 18 min. Phenomenologicalcharacterization of the urinary chromatographic elution pattern wasachieved by RI-detection, set at 40° C. According to the observedpattern, markers were then diagnosed as “Marker A”, “Marker B” or“Marker C” as shown in the attached FIGS. 1-3.

The following materials and equipments have been used in this example:Polyethylene glycol, PH Eur quality, of the average molecular weight 400or 600 from Merck, Darmstadt, Germany; HPLC-grade methanol andacetonitrile from Baker; water deionized and purified by Milliporesystems Elix3 and MilliQ Gradient A10, Inertsil C8-3 5 μm, (250×4.6),and Nucleosil 100 C18 5 μm (50×4.6 mm) HPLC columns from Schambeck SFDGmbH, Bad Honnef, Germany. HPLC-Equipment: sample injector S 5200 fittedwith a 100 μl injection loop, precolumn clean-up pump S 2100, degaserintegrated, six-port motor switching valve ProLAB, column oven SFD125-600, refraction index detector of deflection type, inline filterelement PAT™, for PEEK 3 μm inline filters was obtained from SchambeckSFD GmbH, Bad Honnef, Germany. Analytical pump M480, degassing moduledegasys DG1310 and data acquisition system Chromeleon 6.11 under WindowsNT 4.0 were purchased from Gynkotec.

The invention claimed is:
 1. A method for identifying a urine sample ascoming from an individual, comprising: (a) orally administering two ormore polyethylene glycols of different molecular weights to theindividual; (b) waiting for a length of time sufficient for thepolyethylene glycols to be present in the urine of the individual andthen collecting a urine sample from the individual; (c) investigatingthe urine sample for the presence of the administered polyethyleneglycols to identify the urine sample as coming from the individual; and,(d) performing an assay on the urine sample that directly measures thepresence or amount of an analyte.
 2. The method of claim 1 wherein twopolyethylene glycols of different molecular weights are administered. 3.The method of claim 1 wherein three polyethylene glycols of differentmolecular weights are administered.
 4. The method of claim 1 whereinfour polyethylene glycols of different molecular weights areadministered.
 5. The method of claim 1 wherein said length of time is atleast 30 minutes and no more than four hours.
 6. The method of claim 1wherein said polyethylene glycols of different molecular weights aredetected by means of gas chromatography (GC), gas chromatography/massspectrometry (GC/MS), high performance liquid chromatography (HPLC) orhigh performance liquid chromatography/mass spectrometry (HPLC/MS). 7.The method of claim 1 wherein said individual is an athlete.
 8. Themethod of claim 1 wherein said individual is a drug addict.
 9. Themethod of claim 1 wherein said analyte is a drug.
 10. The method ofclaim 1 wherein said analyte is an intoxicant.
 11. The method of claim 1wherein said analyte is a doping substance.
 12. The method of claim 10wherein said intoxicant is heroin.
 13. The method of claim 10 whereinsaid intoxicant is methadone.
 14. A method for the investigation ofidentifying a urine sample as coming from an individual who is a drugaddict or athlete, comprising: (a) orally administering two or morepolydispersed polyethylene glycols of different average molecularweights to the individual; (b) waiting for a length of time sufficientfor the polyethylene glycols to be present in the urine of theindividual and then collecting a urine sample from the individual; (c)investigating the urine sample for the presence of the administeredpolyethylene glycols to identify the urine sample as coming from theindividual; and (d) performing an assay on the urine sample thatdirectly measures the presence or amount of an analyte selected from thegroup consisting of a drug, intoxicant and doping substance.
 15. Themethod of claim 14 wherein two polydispersed polyethylene glycols ofdifferent average molecular weights are administered.
 16. The method ofclaim 14 wherein three polydispersed polyethylene glycols of differentaverage molecular weights are administered.
 17. The method of claim 14wherein four polydispersed polyethylene glycols of different averagemolecular weights are administered.
 18. The method of claim 14 whereinsaid individual is addicted to heroin.
 19. The method of claim 14wherein said individual is a methadone user.
 20. The method of claim 14wherein said length of time is at least 30 minutes and no more than fourhours.
 21. The method of claim 14 wherein said polydispersedpolyethylene glycols of different average molecular weights are detectedby means of gas chromatography (GC), gas chromatography/massspectrometry (GC/MS), high performance liquid chromatography (HPLC) orhigh performance liquid chromatography/mass spectrometry (HPLC/MS). 22.The method of claim 14 wherein said analyte is a drug.
 23. The method ofclaim 14 wherein said analyte is an intoxicant.
 24. The method of claim14 wherein said analyte is a doping substance.
 25. The method of claim23 wherein said intoxicant is heroin.
 26. The method of claim 23 whereinsaid intoxicant is methadone.
 27. A method for the investigation ofidentifying a urine sample as coming from an individual, comprising: (a)orally administering two or more monodispersed polyethylene glycols ofdifferent molecular weights to the individual; (b) waiting at least 30minutes and no more than four hours after administering to collect for alength of time sufficient for the polyethylene glycols to be present inthe urine of the individual and then collecting a urine sample from theindividual; (c) investigating the urine sample for the presence of theadministered polyethylene glycols to identify the urine sample as comingfrom the individual; and (d) performing an assay on the urine samplethat directly measures the presence or amount of an analyte.
 28. Themethod of claim 27 wherein said analyte is selected from the groupconsisting of a drug, intoxicant and doping substance.
 29. The method ofclaim 27 wherein two monodispersed polyethylene glycols of differentmolecular weights are administered.
 30. The method of claim 27 whereinthree monodispersed polyethylene glycols of different molecular weightsare administered.
 31. The method of claim 27 wherein four monodispersedpolyethylene glycols of different molecular weights are administered.32. The method of claim 27 wherein said length of time is at least 30minutes and no more than four hours.
 33. The method of claim 27 whereinsaid monodispersed polyethylene glycols of different molecular weightsare detected by means of gas chromatography (GC), gaschromatography/mass spectrometry (GC/MS), high performance liquidchromatography (HPLC) or high performance liquid chromatography/massspectrometry (HPLC/MS).
 34. The method of claim 27 wherein theindividual is a drug addict.
 35. The method of claim 27 wherein theindividual is an athlete.
 36. The method of claim 27 wherein the analyteis heroin or methadone.
 37. The method of claim 14 wherein theindividual is an athlete.